In a manufacturing process of an automobile, various vehicle body components are subjected to spot welding, thereafter it is inspected whether the spot welding is properly performed in compliance with the work manual that was previously prepared. In the conventional art, the inspection is made by visual examination, that is, a worker visually checks a spot(s) formed by spot welding.
For example, the worker visually checks a vehicle body component subjected to spot welding to confirm the number and position(s) of a spot(s) formed by spot welding. After that, the worker makes a handwritten entry of results of the inspection in a check sheet or the like.
However, such an inspection technique may cause a human-induced erroneous decision because the decision relies only on the inspector's personal determination.
To solve the problem involved in the inspection technique using the visual examination, below-mentioned Patent Document 1 discloses an inspection system for evaluating a spot using a camera. In the inspection system, a pointer for pointing a spot on a vehicle body component and a camera that is arranged towards an identification section provided on the pointer are used. After the camera has been arranged at a fixed position with respect to the vehicle body component, the camera captures an image of the vehicle body component, and the position of the spot is detected on the basis of a captured image signal from the camera. The detected position of the spot is then collated with a spot position previously recorded to determine whether the detected position of the spot is proper.